MCI

Question 1

MCI

Answer 1

Mild cognitive impairment; Decline cognitive performance greater than expected from
person’s age but not sufficient to warrant diagnosis dementia (no effect IADL)

• Abnormal ageing
• Not necessarily precursor for dementia

Question 2

Diagnosis

Answer 2

Used to be;
- Subjective complaints and objectively decrease of memory at least 1.5 SD under the mean
- other cognitive functions preserved (MMSE = 24)
- IADL and no dementia

Now:
- Concern about change in cognition. Change larger than expected from person’s age, education
- Evidence impairment one or more cognitive domains
- Not in IADL or mild and not demented

Thus no longer memory only 1 - 2 SDs below mean

*overlaps with CIND (cognitive impairment no dementia) in DSM, any cognitive disorder from various causes

Question 3

Causes

Answer 3

Lot of variability, also possible that it reverses to premorbid functioning (rough 17%, most likely in naMCI)

Main causes;
1. Degenerative; eg AD
2. Vascular; eg cerebrovascular disease, precursor for dementia
3. psychiatric; eg depression
4. Traumatic; eg head injury

Question 4

Variants

Answer 4

Amnestic MCI (aMCI)
- memory most impaired
- more prev. variant both in SD and MD

Non-amnestic MCI (naMCI)
- other cognitive domain most impaired (memory can be impaired too, just less)

Single domain (SD)
- 1 cognitive domain affected

Multiple domain (MD)
- Multiple cognitive domains effected
- more likely to develop dementia, especially if memory is included
- MD naMCI more likely to develop LBD

Question 5

Prev

Answer 5

Varies a lot depending on;
- Sampling population (eg memory clinic more aMCI)
- Diagnostic crit (some stricter than others)
- Use of tests (more tests, more sensitive tests etc)
- age (the older the hiigher
- Sex (males higher)

In usa estimate is 16-18% in 70+ age group

Education is protective factor (cog reserve)

SD-aMCI most prev overall + most likely to convert to AD

Question 6

Brain changes

Answer 6

Volumelos slightly less severe than AD, lot larger over time compared to normal ageing.

Cerebral blood flow reduced (level correlated with MMSE performance

More volume reduction in all MCI groups compared to HC
- Volume reduction mainly in temporal and frontal areas
- Volume reduction more extensive in MCI subgroup impaired in both learning and retention (LL LR) than other MCI subgroups (but study may include early stage dementia participants

Question 7

Annual conversion rate

Answer 7

They’re trying to assess the rate of MCI that convert to dementia (eg by making a neuropsychological profile of those persons who are likely to progress to dementia).

Currently lot of variance in the rate (3-63%), the larger the follow up duration the higher the rate.

Depends on;
- sample pop (clinic = higher)
- nature of complaint (spontaneous = higher)
- number and type of cog domains assessed (more =higher)
- how dementia was ruled out (failure to detect = lower)

Meta analysis; 6.7 ACR
- 9.6 in clinical, 4.9 in communitie
- roughly 45% of MCI remain stable

Question 8

Focus points for assessment

Answer 8

medical; rule out medical cause

clinical interview; onset/course, linked with event or slow onset (as usual in neurcog disease)

Subjective complaints (early stage more likely to acknowledge, later stage dement more likely to underestimate)